The present invention relates to a method of cooling a brain.
For many years it has been known that deep hypothermia (less than 32xc2x0 C.) can improve survival from ischemic brain injuries. The practicalities of these treatments preclude its use in acute stroke. The patient has to be paralyzed and placed on a ventilator for 48 hours for the treatment effect to be seen. Recently, some articles were published that indicated benefits to the ischemic brain of modest hypothermia (35xc2x0 C.) which is two degrees below normal body temperature. In both studies the practicality issue is apparent by use of cooling blankets on the patients. This requires the patient to remain bedridden and/or paralyzed and on the ventilator to obtain the apparent positive outcome. The complications of bedridden patients are well known (i.e. pulmonary embolus, pressure sores, and pneumonia). Several solutions for cooling body parts have been suggested in U.S. Pat. Nos. 5,916,242; 4,566,455; 4,750,493; 4,763,866; 4,020,963; 5,190,032; 5,486,204; 5,643,336; 5,897,581; 5,913,855; 5,057,964; 6,030,412. Some of these patents deal with cooling of a patient""s brain which can be performed by various apparatuses, for example by a circular collar applied over the whole periphery of the neck. The existing apparatuses can be further improved.
Accordingly, it is an object of the present invention to provide a method of cooling a brain, which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a method of cooling of a brain which includes the steps of applying each of two hollow pads exclusively to an area of a patient""s neck adjoining one of carotid arteries so that when applied said hollow pads contact the areas exclusively adjacent to the carotid arteries and are spaced from one another; and supplying by liquid circulating means a cooling liquid from a liquid source to a respective one of said pads and withdrawing the liquid from the same pad, whereby the cooling liquid can circulate either through one of said pads independently from the other of said pads, or the cooling liquid can circulate through the other of said pads independently from one of said pads, or both said pads, to cool either one half of the brain, or another half of the brain, or both halves thereof.
When the method is performed in accordance with the present invention, it becomes possible for the first time to selectively cool either a left part of the brain or a right part of the brain, or both parts simultaneously. This is important because in some instances it is necessary to cool only one half of the brain when this half of the brain is damaged. Also, the remaining part of the neck between the areas of the carotid arteries are not cooled, since cooling of this remaining part is undesirable especially in view of increased sensitivity of the back of the neck. When it is exactly determined which part of the brain is damaged by a stroke, then a corresponding one of the pads which is applied on the area of the carotid artery leading to the damaged part of the brain in cooled, and cooled blood flows to the damages part of the brain. In emergency situations it is possible to activate the cooling liquid circulation through both pads before a determination is made which part of the brain is damaged, to make sure that hypothermia is immediately administered. Thereafter, when it is determined which part of the brain is damaged, the cooling is concentrated exclusively on the carotid artery leading to the damaged part of the brain.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.